Apparatus for controlling the upward and downward movements of an elevator

ABSTRACT

An apparatus for controlling the upward and downward movements of a piston rod of a hydraulically operated cylinder on a base in which a bracket is rigidly mounted on the cylinder and upper and lower rotary members are rotatably mounted on the base and bracket, respectively. A control rod having its top end operably connected to the piston rod extends in parallel with the latter and slidably through the center of the upper rotary member and through the bracket so that the control rod is axially movable with the piston rod. The upper and lower rotary members have mounted thereon sets of elongated stops having different lengths and extending toward each other so that each of the upper stops cooperates with the corresponding lower stop to define therebetween a gap of a dimension different from those defined between other pairs of stops. The control rod has an engagement member extending laterally therefrom. The rotary members are rotatable to move a selected pair of stops into the path of the movement of the engagement member so that the latter engages the selected pair of stops. Limit switches are provided to discontinue the fluid pressure supply to the cylinder when the engagement takes place.

11] 3,822,635 July 9, 1974 United States Patent [191 Nishimura [57] ABSTRACT An apparatus for controlling the upward and downward movements of a piston rod of a hydraulically operated cylinder on a base in which a bracket is rigidly mounted on the cylinder and upper and lower rotary members are rotatably mounted on the base and APPARATUS FOR CONTROLLING THE UPWARD AND DOWNWARD MOVEMENTS OF AN ELEVATOR [75] Inventor: Matsuo Nishimura, Tokyo, Japan [73] Assignee: Yasui Sangyo Company Limited,

Shlzuoka'ken Japan bracket, respectively. A control rod having its top end Nov. 20, 1972 operably connected to the piston rod extends in paral- [21] Appl. No.: 305,506

[22] Filed:

lel with the latter and slidably through the center of the upper rotary member and through the bracket so that the control rod is axially movable with the piston rod. The upper and lower rotary members have [52] US. 91/410, 91/445, 92/131, 92/l3.5

mounted thereon sets of elongated stops having different lengths and extending toward each other so that each of the upper stops cooperates with the corresponding lower stop to define therebetween a gap of a 00 5 054 U m wo 1 53M 11. F ,9 4 NB 3 l! 1 b 5U J9 h c r mm m d Ld .mm. UN 55 ll dimension different from those defined between other [56] References Cited pairs of stops. The control 'rod has an engagement UNITED STATES PATENTS member extending laterally therefrom. The rotary members are rotatable to move a selected pair of stops into the path of the movement of the engagement member so that the latter engages the selected pair of stops. Limit switches are provided to discontinue the fluid pressure supply to the cylinder when the engagement takes place.

2,648,096 8/1953 Baigent................................ 3,080,852 3/1963 Geyer......................... 3,282,283 11/1966 Takeda..................................... 3,430,538 3/1969 Primary Examiner-Paul E. Maslousky Attorney, Agent, or Firm-Holman & Stern 2 Claims, 1 Drawing Figure SUPPLY VALVE TO HYDRAULIC FLUID SUPPLY PATENTEU JUL 9 TO INPUT TO INPUT L WW E n u P P W W W W 6 H U 2| VCC HM SUPPLY FLUID SUPPLY APPARATUS FOR CONTROLLING THE UPWARD AND DOWNWARD MOVEMENTS OF AN ELEVATOR BACKGROUND OF THE INVENTION The present invention relates to an apparatus for controlling the upward and downward movements of the piston rod of a hydraulically operated device such as an arm of a manipulator.

SUMMARY OF THE INVENTION According to the present invention, there is provided an apparatus for controlling the upward and downward movements of an elevator having a cylinder on a base and a piston rod of a piston slidable in said cylinder so as to be actuated by a fluid pressure supplied into said cylinder, said apparatus comprising a horizontal bracket mounted on said cylinder, an upper rotary member mounted on the bottom surface of said bracket for rotation relative to said bracket in a horizontal plane, a control rod parallel with said piston rod and extending slidably through said bracket and through the central area of said upper rotary member, a connecting member interconnecting the upper ends of said control rod and said piston rod, a lower rotary member mounted on said base for rotation in a horizontal plane with respect to said base, sets of stops on the opposed faces of said upper and lower rotary members, each set including a plurality of stops having different lengths and disposed on a circle in an equally spaced relationship with each other, the upper and lower sets of stops forming a plurality of pairs of stops, an engagement member on said control member extending laterally therefrom, means for causing a selected pair of stops to be moved into vertical alignment with said engagement member, and means to discontinue the supply of said fluid pressure to said cylinder when said engagement member is engaged with said selected pair of stops whereby the upward and downward movements of the pitson rod are discontinued.

In a preferred embodiment of the invention, the upper and lower rotary members may be formed with teeth in the outer peripheries thereof. A gear may be preferably provided in meshing engagement with-the teeth of each of the upper and lower rotary members. The causing means may preferably be in the form of a rotary motor which can be actuated by means of a switch to drive the gear so that the associated rotary member is rotated step by step an angle equal to the angle between each adjacent pair of said set of stops.

BRIEF DESCRIPTION OF THE DRAWINGS The above and other objects, features and advantages of the invention will be made apparent by'the following description with reference to the accompanying drawing in which the sole FIGURE illustrates in partial sectional side elevation an embodiment of an apparatus for controlling the upward and downward movements in a lift mechanism according to the present invention.

DETAILED DESCRIPTION OF THE INVENTION Referring to the drawing, reference numeral 1 denotes a vertical hydraulic cylinder mounted on a base 2. A piston 3 having a piston rod 4 is mounted in the cylinder 1 for axial sliding movement therein. The cylinder 1 is provided with hydrualic fluid supply ports 5 and 6 at the top and bottom ends thereof so that the piston 3 and the piston rod 4 are moved upwardly by the hydraulic fluid supplied through the port 6 while the piston and piston rod are downwardly movable by the hydraulic fluid supplied through the port 5.

A horizontal bracket 7 is fixedly mounted on the cylinder l at the upper end portion thereof. An upper, disc-like rotary member 8 is mounted on the bottom surface of the bracket 7 for rotation in a horizontal plane relative to the bracket. The rotary member 8 has its outer periphery formed with teeth 9 which are in meshing engagement with a driving gear 10 mounted on the bracket 7 for rotation in a horizontal plane. The driving gear 10 is adapted to be rotated a predetermined angle step by step by means of an upper rotary motor 11 which is also mounted on the bracket 7.

A control rod 12 which is parallel with the piston rod 4, extends slidably through the central area of the upper rotary member 8 and through the bracket 7. The controlling rod 12 has its top end connected to the top end of the piston rod 4 by means of a horizontal connecting member 13 while the bottom end of the controlling rod 12 is connected with an engagement member 14 extending laterally with respect to the rod 12.

A lower, disc-like rotary member 15 is mounted on the base 2 for rotation in a horizontal plane with respect to the base and is positioned in vertically opposed relationship with the upper rotary member 8. The lower rotary member 15 is formed with teeth 16 in the outer periphery thereof, with the teeth 16 being meshed with a second driving gear 17 mounted rotatably on the base 2. The second driving gear 17 is adapted to be rotated step by step by a second rotary motor 18 in a direction the same as the direction in which the upper rotary member 8 is rotated. The arrangement is such that the angle of rotation of the lower rotary member 15 in each step is the same as that of the upper rotary member 8.

Each of the first and second rotary motors 11 and 18 is designed to be actuated independently from the other motor by means of an associated switch, not shown.

The upper rotary member 8 is provided with a plurality of elongated upper stops 19-1, 19-2 l9-n disposed on a circle in an equally spaced relationship with respect to each other. The upper stops are preferably threaded and extend through the upper rotary member 8 and are fastened thereto by means of stop nuts engaging the bottom surface of the rotary member 8, as will be seen in the drawing. The upper stops 19-1 19-n have different lengths as measured between the bottom surface of the upper rotary member 8 and the bottom ends of the stops 19-1 l9-n. The lengths may be adjusted by screwing down or out the stops with respect to the upper rotary member and re-tightening the nuts thereto.

The lower rotary member 15 is also provided with a plurality of elongated lower stops 20-1, 20-2 20-n respectively corresponding to the upper stops 19-1, 19-2 19-n. The lower stops are similarly disposed on a circle in an equally spaced relationship with respect to each other and extend upwardly from the lower rotary member 15 in such a manner that the lower stops have different lengths as measured between the top ends thereof and the top surface of the lower rotary member 15. The lengths are similarly adjustable.

The upper and lower rotary members 8 and 15 are so designed that each of the rotary members is rotated an angle the same as the angle between each adjacent pair of the stops at each time when the associated rotary solenoid 11 or 18 is activated.

The apparatus of the invention is so arranged that the hydraulic fluid supply through the lower supply port 6 into the hydraulic cylinder 1 is discontinued when the engagement member 14 on the control rod 12 is engaged by any one of the upper stops 19-1 19-n on the upper rotary member 8 while the hydraulic fluid supply through the upper supply port into the hydraulic cylinder 1 is discontinued when the engagement member 14 is engaged by any one of the lower stops 20-1 20-n on the lower rotary member 15. For this purpose, limit switches my be mounted either on the ends of the upper and lower stops or on the top and bottom surfaces of the engagement member 14 as at 140 and 14b so that the limit switches when actuated operate valve members V and V in a hydraulic fluid supply circuit (not shown) connected to the fluid supply ports 5 and 6 via a valve control circuit A.

With the construction and arrangement described above, when the piston rod 4 in the hydraulic cylinder 1 is required to be upwardly moved the greatest distance, the upper and lower rotary motors 11 and 18 will be activated to rotate the upper and lower rotary members 8 and to a position in which the shortest upper and lower stops 19-1 and 20-1 are vertically aligned with the engagement member 14 on the control rod 12. Then, the hydraulic fluid is supplied through the upper supply port 5 into the cylinder to lower the piston rod 4 together with the control rod 12 until the bottom surface of the engagement member 14 is brought into en-- gagement with the top of the shortest lower stop 20-1 so that the hydraulic fluid supply through the upper supply port 5 is discontinued to keep the control rod 12 stationary at its lowermost position.

Then, the hydraulic fluid will be fed through the lower supply port 6 into the cylinder 1 to cause the piston rod 4 to be moved upwardly together with the control rod 12. When the engagement member 14 on the rod 12 is brought into engagement with the bottom end of the shortest upper stop 19-1, an associated limit switch is actuated to discontinue the hydraulic fluid supply through the lower supply port 6 with a result that the upward movement of the piston rod 4 is discontinued.

Thus, the piston rod 4 has been upwardly moved a distance equal to the distance between the shortest, upper and lower stops 19-1 and 20-1 minus a dimension corresponding to the thickness of the engagement member 14.

The piston rod 4 may then be moved downwardly by the fluid pressure supply through the upper supply port 5 into the hydraulic cylinder 1. When the engagement member 14 contacts the top end of the shortest lower stop 20-1, an associated limit switch will be actuated to change-over a valve in the hydraulic fluid supply circuit so that the fluid pressure supply through the upper supply port 5 is discontinued to cause the piston rod 4 to rest at its lowermost position.

When the piston rod 4 is required to be upwardly moved a distance lesser than the distance substantially equal to the shortes upper and lower stops 19-1 and 20-1, another appropriate pair of upper and lower stops may be selected and the apparatus will be similarly operated to bring the selected pair of stops into vertical alignment with the engagement member 14 on the rod 12.

As will be apparent from the above description, the upward and downward movements of the piston rod are stopped by the engagement of the engagement member 14 of the rod 12 with selected upper and lower stops on the upper and lower rotary members 8 and 15, respectively' Thus, the apparatus will be suited for use to control the upward and downward movements of an elevator such as an arm of a manipulator.

What is claimed is;

1. An apparatus for controlling the upward and downward movements of an elevator having a cylinder on a base and a piston rod of a piston slidably mounted in said cylinder so as to be actuated by a fluid pressure supplied into said cylinder, said apparatus comprising a horizontal bracket mounted on said cylinder, an upper rotary member mounted on the bottom surface of said bracket for rotation relative to said bracket in a horizontal plane, a control rod parallel with said piston rod and extending slidably through said bracket and through a central area of said upper rotary member, a connecting member interconnecting the upper ends of said control rod and said piston rod, a lower rotary member mounted on said base for rotation in a horizontal plane with respect to said base, sets of stops on opposed faces of said upper and lower rotary members, each set including a plurality of stops having different lengths and disposed on a circle in an equally spaced relationship with each other, the upper and lower sets of stops forming a plurality of pairs of stops, an engagement member on said controlling rod extending laterally therefrom, means for causing a selected pair of stop to be moved into vertical alignment with said engagement member, and means to discontinue the supply of said fluid pressure to said cylinder when said engagement member is engaged with said selected pair of stops whereby the upward and downward movements of the piston rod are discontinued.

2. The apparatus as defined in claim 1, in which said upper and lower rotary members are provided with teeth in the outer peripheries thereof, a gear in meshing engagement with the teeth of each of said upper and lower rotary members, and a rotary motor for driving said gear so that the associated rotary member is rotated step by step an angle equal to the angle between each adjacent pair of said set of stops. 

1. An apparatus for controlling the upward and downward movements of an elevator having a cylinder on a base and a piston rod of a piston slidably mounted in said cylinder so as to be actuated by a fluid pressure supplied into said cylinder, said apparatus comprising a horizontal bracket mounted on said cylinder, an upper rotary member mounted on the bottom surface of said bracket for rotation relative to said bracket in a horizontal plane, a control rod parallel with said piston rod and extending slidably through said bracket and through a central area of said upper rotary member, a connecting member interconnecting the upper ends of said control rod and said piston rod, a lower rotary member mounted on said base for rotation in a horizontal plane with respect to said base, sets of stops on opposed faces of said upper and lower rotary members, each set including a plurality of stops having different lengths and disposed on a circle in an equally spaced relationship with each other, the upper and lower sets of stops forming a plurality of pairs of stops, an engagement member on said controlling rod extending laterally therefrom, means for causing a selected pair of stop to be moved into vertical alignment with said engagement member, and means to discontinue the supply of said fluid pressure to said cylinder when said engagement member is engaged with said selected pair of stops whereby the upward and downward movements of the piston rod are discontinued.
 2. The apparatus as defined in claim 1, in which said upper and lower rotary members are provided with teeth in the outer peripheries thereof, a gear in meshing engagement with the teeth of each of said upper and lower rotary members, and a rotary motor for driving said gear so that the associated rotary member is rotated step by step an angle equal to the angle between each adjacent pair of said set of stops. 